1. Field of the Invention
The present invention relates generally to motorized transportation vehicles, and more specifically to an aircraft having a configuration allowing it to be interchangeably converted to a roadable vehicle. The aircraft includes numerous novel features relating to the practicality and safety of such a vehicle, such as the folding or removal of the flight components, engine and drive system, landing gear and wheel system, and other novel features and components.
2. Description of the Related Art
The goal of a motor vehicle which is capable of both flight and operation on the roads and highways, has been a dream since shortly after the development of the first powered aircraft in the early part of the twentieth century. Numerous persons have attempted to produce such a combination machine, generally known as a flying car or roadable aircraft. Many of these attempts have been successful, and in two cases the machines have been type certificated by the Civil Aeronautics Agency (now the Federal Aviation Administration) as production aircraft.
However, none of these various machines have been particularly practical or commercially successful, primarily due to the vast difference in structural requirements for the two different environments. In order to be truly practical, the flight components of the vehicle must be capable of being carried by, or with, the remainder of the vehicle during ground operations, which lessens the capacity of the land vehicle. Accordingly, the flight components must be relatively small and quite efficient, in order to be capable of being carried or towed readily by the remainder of the vehicle on the ground.
The other side of this problem is that in order to produce an efficient aircraft, the structure must be relatively lightweight, which is at odds with the requirements for a ground vehicle and the constant abuse such a vehicle must endure over rough and potholed surfaces. When the ground portion of the vehicle is built sufficiently strongly to accept the stresses of road and highway use, flight performance suffers due to the weight of the vehicle. In some instances, this has resulted in flight components which could not be disassembled or folded to the extent required to allow carriage or towing by the ground portion of the vehicle. Again, while some attempts at producing such a hybrid vehicle have met with limited success, none to the present have been truly successful, primarily due to the obstacles noted above.
A discussion of the related art of which the present inventor is aware, and its differences and distinctions from the present invention, is provided below.
U.S. Pat. No. 2,713,465 issued on Jul. 19, 1955 to Harry E. Novinger describes a Combined Air-Ground Vehicle having an airfoil shaped forward fuselage or body and an upwardly and rearwardly disposed wing, resulting in a negative stagger biplane configuration. The fuselage and rearward wing are connected by large side members serving as end or tip plates for the relatively low aspect ratio fuselage and wing. The flight components cannot be folded or disassembled for ground use of the vehicle, as in the present roadable aircraft, with Novinger's short span, low aspect ratio upper wing and fuselage having a width allowing for unrestricted travel on the road. The tricycle wheel arrangement of the Novinger machine is unlike the more stable rhomboid pattern of the wheels of the present roadable aircraft.
U.S. Pat. No. 2,767,939 issued on Oct. 23, 1956 to Moulton B. Taylor describes a Flying Automotive Vehicle Assembly, comprising a left and right wing structure, tail cone structure, and empennage, all of which are separable from a central automobile or cabin structure. While the wings fold rearwardly, as in the present roadable aircraft, they fold against the tail cone of the assembly, which is removed from the automobile or cabin structure and towed therebehind for road use. The automobile or cabin structure is built extremely lightly for efficiency as an aircraft, with relatively small and light wheels and tires serving for both road use and for takeoffs and landings. This is one of only two roadable aircraft or flying car designs ever certificated for production by the CAA or FAA.
U.S. Pat. No. 2,940,688 issued on Jun. 14, 1960 to Edward F. Bland describes a Roadable Aircraft And Sailboat having a lifting body configuration somewhat in the manner of the fuselage shape of the Novinger craft discussed further above. However, the rear fuselage includes a central channel before the rear propeller, somewhat in the manner of one nacelle or channel of the twin engine Custer Channel Wing aircraft developed in the 1950s. The Bland craft also includes folding wings, which may be folded with their spans rearwardly atop the fuselage for road use, or which may be extended vertically to serve as sails. The craft includes many features which increase the weight significantly, and thus utilizes two engines, one for road and water use and the other for airborne use. However, the two engines may be linked together to provide the required power for takeoff and climb when used as an aircraft. This arrangement is unlike the single engine configuration of the present roadable aircraft.
U.S. Pat. No. 3,012,737 issued on Dec. 12, 1961 to David R. Dodd describes a Combination Land And Air Vehicle having a twin boom tail assembly and folding wings. The wings, however, fold in a spanwise direction as well as at the roots, with the leading portion folding forwardly and horizontally next to the fuselage, and the rearward portion folding downwardly to form an essentially vertical surface parallel to the fuselage sides when folded. The tail assembly does not fold, as in the present roadable aircraft. Also, the tricycle wheel configuration is unlike the rhomboid wheel configuration of the present craft.
U.S. Pat. No. 3,371,886 issued on Mar. 5, 1968 to Robert O. Schertz describes an Aircraft Adapted For Highway Usage, having a rearwardly disposed main wing and a forwardly disposed canard surface. The basic fuselage structure and four wheel configuration are somewhat like those of the Taylor flying automobile assembly discussed further above, but the Schertz fuselage is relatively short coupled in that no separable tail cone is provided. Rather, Schertz places vertical tail surfaces extending upwardly from the rearwardly disposed wing, and relies upon the forward canard surfaces for pitch control in flight. The wings each include a double folding mechanism, and fold with both portions of each wing in a vertical plane alongside their respective vertical surfaces for highway use, but do not fold rearwardly to lower the height of the vehicle for road use, as in the present roadable aircraft.
U.S. Pat. No. 4,269,374 issued on May 26, 1981 to Harvey R. Miller describes a Combined Road Vehicle And Aircraft, in which the wings, tail assembly, and propeller drive all fold into the structure of the body or cabin portion for carriage during road use. The wings fold along the spar, similarly to the folding configuration of the Dodd craft discussed further above. The wheel arrangement is a conventional rectangular configuration, except that the non-driven rear wheels are capable of inward articulation to provide room for the wings when folded. The front wheels are driven for road use. The lack of intermediate folding for the wings, conventional wheel layout, and other features result in a craft unlike that of the present invention.
U.S. Pat. No. 4,778,129 issued on Oct. 18, 1988 to Frank Byford describes a Control Surface Drive For Folding Wing Aircraft, wherein the control surfaces remain connected at all times when the wing is folded or extended. The Byford control linkage cannot be used with a wing folding system where the wing is rotated about a spanwise axis during one step of the folding process, as in the present roadable aircraft invention. The rotational and rearward folding of the wing of the present roadable aircraft is not adaptable to the Byford control linkage, and uses a different principle of connecting the flight controls when the wings and tail assembly are extended for flight. The present system disconnects the flight controls when the flight components are folded, unlike the Byford control linkage.
U.S. Pat. No. 4,881,701 issued on Nov. 21, 1989 to Gary M. Bullard describes a Combination Automobile And Airplane having a two place tandem, pusher engine, canard configuration, somewhat like the configuration of the Vari-Eze and Long-Eze aircraft designs of Burt Rutan. However, the canard tips each include a steerable front wheel therein, and two rear wheels extend below the rearward main lifting surface and are driven by shafts extending outwardly below the inboard portions of the wing. The outboard portions of the wing are capable of double folding to lie over the top of the rear fuselage for road use. The propeller is not removable or foldable, but is disengaged for road use. No folding tail boom structure or rearwardly folding wing structure is provided, as is provided in the present roadable aircraft.
U.S. Pat. No. 5,050,817 issued on Sep. 24, 1991 to Harvey R. Miller describes a Combined Road And Aircraft Vehicle of a similar configuration to the vehicle of the '374 U.S. Patent to the same inventor, discussed further above. The primary difference is that the vehicle of the '817 Patent stores the wings along the sides of the road vehicle, rather than in storage compartments in the sides of the road vehicle, as in the '374 Patent. Other features, e. g., tail folding, are similar between the two Miller patents, and are unlike the means used in the present invention.
U.S. Pat. No. 5,435,502 issued on Jul. 25, 1995 to Kenneth G. Wernicke describes a Flying And Road Vehicle of a configuration similar to that of the '465 U.S. Patent to Novinger discussed further above, i. e., having a relatively low aspect ratio wing to meet maximum road width requirements without folding. None of the Wernicke flight components are foldable, unlike the multiple folding flight components of the present roadable aircraft.
Finally, a publication titled Roadable Aircraft--From Wheels To Wings, by Palmer Stiles, copyright 1994 and published by Custom Creativity, Inc., Melbourne, Fla., includes a comprehensive, but not exhaustive, collection of at least portions of U.S. Utility and Design Patents issued for roadable aircraft and flying automobiles. None of the patents published in the book, but not discussed in detail further above, are felt to be more closely related to the present invention than those discussed herein.
None of the above inventions and patents, either singly or in combination, is seen to describe the instant invention as claimed.